全文获取类型
收费全文 | 4161篇 |
免费 | 190篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 33篇 |
综合类 | 7篇 |
化学工业 | 958篇 |
金属工艺 | 115篇 |
机械仪表 | 77篇 |
建筑科学 | 133篇 |
矿业工程 | 5篇 |
能源动力 | 185篇 |
轻工业 | 452篇 |
水利工程 | 41篇 |
石油天然气 | 11篇 |
无线电 | 294篇 |
一般工业技术 | 851篇 |
冶金工业 | 631篇 |
原子能技术 | 11篇 |
自动化技术 | 554篇 |
出版年
2024年 | 10篇 |
2023年 | 54篇 |
2022年 | 125篇 |
2021年 | 179篇 |
2020年 | 102篇 |
2019年 | 130篇 |
2018年 | 166篇 |
2017年 | 136篇 |
2016年 | 127篇 |
2015年 | 103篇 |
2014年 | 143篇 |
2013年 | 287篇 |
2012年 | 217篇 |
2011年 | 306篇 |
2010年 | 217篇 |
2009年 | 200篇 |
2008年 | 209篇 |
2007年 | 201篇 |
2006年 | 127篇 |
2005年 | 126篇 |
2004年 | 106篇 |
2003年 | 91篇 |
2002年 | 88篇 |
2001年 | 71篇 |
2000年 | 56篇 |
1999年 | 58篇 |
1998年 | 49篇 |
1997年 | 51篇 |
1996年 | 55篇 |
1995年 | 50篇 |
1994年 | 50篇 |
1993年 | 43篇 |
1992年 | 48篇 |
1991年 | 25篇 |
1990年 | 27篇 |
1989年 | 25篇 |
1988年 | 25篇 |
1987年 | 33篇 |
1986年 | 24篇 |
1985年 | 23篇 |
1984年 | 27篇 |
1983年 | 30篇 |
1982年 | 30篇 |
1981年 | 22篇 |
1980年 | 19篇 |
1979年 | 8篇 |
1978年 | 9篇 |
1977年 | 5篇 |
1976年 | 23篇 |
1975年 | 4篇 |
排序方式: 共有4358条查询结果,搜索用时 359 毫秒
1.
2.
Brian Lawn David Marshall Rishi Raj Greg Hirth Trevor Page Julie Yeomans 《Journal of the American Ceramic Society》2021,104(1):23-26
Crystalline quartz has long been identified as among the weakest of abundant crustal minerals. This weakness is particularly evident around the α–β phase inversion at 573°C, in which Si–O bonds undergo a displacive structural transformation from trigonal to hexagonal symmetry. Here we present data using indentation testing methodologies that highlight the precipitous extent of the transformational weakening. Although the indentations are localized over relatively small specimen contact areas, the data quantify the essential deformation and fracture properties of quartz in a predominantly (but not exclusively) compressive stress field, at temperatures and pressures pertinent to conditions in the earth's crust. 相似文献
3.
Manik Chandra Biswas Samit Chakraborty Abhishek Bhattacharjee Zaheeruddin Mohammed 《Advanced functional materials》2021,31(19):2100257
Shape memory materials (SMMs) in 3D printing (3DP) technology garnered much attention due to their ability to respond to external stimuli, which direct this technology toward an emerging area of research, “4D printing (4DP) technology.” In contrast to classical 3D printed objects, the fourth dimension, time, allows printed objects to undergo significant changes in shape, size, or color when subjected to external stimuli. Highly precise and calibrated 4D materials, which can perform together to achieve robust 4D objects, are in great demand in various fields such as military applications, space suits, robotic systems, apparel, healthcare, sports, etc. This review, for the first time, to the best of the authors’ knowledge, focuses on recent advances in SMMs (e.g., polymers, metals, etc.) based wearable smart textiles and fashion goods. This review integrates the basic overview of 3DP technology, fabrication methods, the transition of 3DP to 4DP, the chemistry behind the fundamental working principles of 4D printed objects, materials selection for smart textiles and fashion goods. The central part summarizes the effect of major external stimuli on 4D textile materials followed by the major applications. Lastly, prospects and challenges are discussed, so that future researchers can continue the progress of this technology. 相似文献
4.
Kumar Kuila Saikat Kumbhakar Partha Sekhar Tiwary Chandra Kumar Kundu Tarun 《Journal of Materials Science》2022,57(19):8658-8675
Journal of Materials Science - Hybrid oxidation methodologies (HOMs) and active site enrichment of 2D nanocatalyst through defects induction are ubiquitously used for generating adequate reactive... 相似文献
5.
6.
7.
8.
9.
Madhu H. C. Edachery Vimal Lijesh K. P. Perugu Chandra Shekhar Kailas Satish V. 《Metallurgical and Materials Transactions A》2020,51(8):4086-4099
Metallurgical and Materials Transactions A - Hybrid nanocomposites have potential as wear-resistant materials. However, synthesizing these nanocomposites by conventional molten state methods result... 相似文献
10.